K.C.
Your best bet is to contact a few local electricians. Prices can vary significantly throughout the country. If you get three quotes you will usually have a good handle on price ranges.
Wesley
Cape Design Build
Www.capedesignbuild.com
If you have an electrical outlet located behind the bed and the walls are purlin (nailer blocks in the wall) free ,$300.00 is a good estimate. If the outlet is dead center of the head board, you may have to have a bit of wire mold (raceway) ran to protect wiring.
You may want to add a wall switch to operate the sconce lighting. If you have access to power on the same wall, (ie: an outlet) then it is a little less expensive. Wire will need to be run inside the wall from the power source to the fixtures and switch, and could run between $250-$450 depending on the available access.
$500